萼脊兰AP1-like基因的克隆与表达分析

Cloning and Expression Analysis of AP1-like Gene fromSedirea japonica

采用RT-PCR和RACE技术从萼脊兰(Sedirea japonica)花瓣中分离到1个MADS-box A类基因,该基因命名为AP1-like(登录号JQ776636)。AP1-like基因的cDNA全长1 221bp,包含1个753bp的开放阅读框(ORF),共编码250个氨基酸。蛋白序列比对和进化树分析表明,AP1-like蛋白与蝴蝶兰ORAP11蛋白的一致性为96%,进化距离最近。二级结构分析表明,该蛋白分子属于亲水性蛋白,其中有53.60%的α螺旋、7.20%的延伸链、39.20%的不规则折叠。实时荧光定量PCR分析表明,萼脊兰AP1-like基因在盛花期的根和叶中表达量最高;在生殖器官中花蕾期花葶的表达量最高,其次是花蕾;盛花期中花葶的表达量最高,子房和合蕊柱的表达量次之,萼片、花瓣、唇瓣均有微量表达。研究认为,AP1-like可能在调控植物由营养生长向生殖生长过渡阶段及子房的建成中起重要作用。

A MADS-box gene was isolated from the petal of Sedirea japonica by using RT-PCR and RACE approaches and the gene was named AP1-like（The accession number in GenBank：JQ776636）.The full length cDNA of AP1-like is 1 221 bp,with an ORF of 753 bp encoding 250 putative amino acid residues.Multiple sequence alignment and phylogenetic tree analyses showed that AP1-like is close to ORAP11 from Phalaenopsis amabilis with an 96% sequence similarity.This protein is hydrophilic and contains 53.60% α-helical domains,7.20% extended strand,39.20% random coil.The expression was analyzed by real-time fluorescent quantitative PCR and this gene was expressed in different parts in different periods,but expression abundance was different.In roots and leaves,the highest amount of expression was observed during full-bloom stage,In the reproductive organs,the highest expression level of AP1-like was detected in scapes,followed by in buds during the bud period.The expression level of AP1-like in scapes showed higher than that in ovaries and columns during full-bloom period.The expression of AP1-like in sepals and petals and lips showed the lowest level.The results showed that this gene may play an important role in regulating the transition from vegetative growth to reproductive growth and the ovary development.